There is no denying that Sarah is extremely ditzy, and often comes across as an idiot. However, her power definately makes it much easier for the sisters to capture children. Also, there are at least a few times where there sisters could have lived if they had listened to her.

1. When Winnie is trying to remember the last ingrediant to the potion, Sarah tells her what it is, but Mary tells her to hush, and Winnie ignores her. Obviously this was played for comedy, but it was definately a moment where they should have listened to Sarah.

2. After Max dumps out their potion, they have enough left...